HIGHLY POROUS SEPARATOR FILM HAVING A COATING AND A DISCONNECTING FUNCTION

摘要

The invention relates to a biaxially oriented single layer or multilayer porous film which comprises at least one porous layer wherein said layer contains at least one propylene polymer and polyethylene (i) the porosity of the porous film is 30% to 80% and (ii) the permeability of the porous film is < 1000 s (Gurley value) characterized in that (iii) the porous film has an inorganic preferably ceramic coating (iv) the coated porous film has a Gurley value of < 1500 s and (v) the coated porous film has a Gurley value of > 6000 s when said film is heated above 140° C for 5 min. The coated porous film has a double safeguard. The invention further relates to a method for producing such a film and to the use thereof in high energy or high power systems in particular in lithium lithium ion lithium polymer and alkaline earth batteries.